This invention relates to railroad car brake systems. More particularly, the invention relates to a wheel truck mounted brake system which is load sensitive and compensates for different weight loads on the truck.
Brake systems for double axle wheel trucks generally include brake shoes mounted on opposite ends of a pair of brake beams which are positioned between the axles, the beams being movable away from each other to press the shoes into engagement with the wheels. Customarily, these brake systems include a cylinder and piston for actuating the brake shoes into frictional engagement with the wheels. The cylinder and piston can either be mounted on the railroad car which the wheel truck supports, "car mounted", or can be mounted on the wheel truck, "truck mounted." In both cases, a multiple lever system interconnects the piston and the brake beams for operation of the brakes.
One of the problems arising in all railroad car brake systems is that the load imposed by the cars on their respective wheel trucks can vary considerably from car to car. Thus, in a single train, some cars may be fully loaded, some partially loaded, and some empty. Consequently, if uniform pressure is applied to the pneumatic means, i.e., the piston/cylinder, for the wheels of all the cars, the braking effect will be much higher on partially loaded and empty cars than on fully loaded cars and is undesirable.
The present invention is directed to a simple, light weight truck mounted brake system for wheel trucks which automatically compensates for different loads imposed on the trucks, and which provides for uniform braking for different loaded cars. The brake system of this invention uses standard truck components and brake beams, provides high braking efficiency, and includes automatic slack adjustment for brake shoe wear.